Valve.



A. C. STEWART.

VALVE. APPLIOATION FILED NOV. 22, 1909.

1,005,581 Patented Oct. 10, 1911.

A, jimi/(6):

UnrTnn sTaTns PATENT ornion.

VALVE.

To all whom 1' t may concer/1i:

Be it known that I, ALFRED C. STEWART, a citizen of the United States,residing at Los Angeles, in the county of Los Angeles and State ofCalifornia, have'invented a new and useful Valve, of which the followingis a specification.

This invention relates to valves particularly adapted for pneumatictires, and the main object of the invention is toprovide a valve whichmay be readily screwed to the valve stem of a pneumatic tire as asubstitute for the regular valve, which, when the regular valve isremoved and the substitute valve is applied, will produce a large airassage making it much easier to inflate the tire than with the originalvalve and to also provide a positive closure after inflation which willabsolutely prevent leakage.

In the ordinary7 valve for pneumatic tires leakage often occurs owing tothe imperfect closure of the valve against its seat, which closure isordinarily effected by. spring pressure 'and by the pressure of the airwithin the tire. Leakage is also apt to occur at the imperfect closurebetween the cap and end of the valve stem. In the present invention thevalve is closed against its lower seat after inflation, and means areprovided whereby the valve ismechanically and positively forced tightagainst its lower seat, thereby absolutely preventing leakage' as thecap is not depended upon as in the ordinary type of valve.

While the present invention does not absolutely necessitate the removalof the regir lar valve, nevertheless, when the present invention isemployed it is contemplated that the regular valve should be removed asits presence would nullify the ease of inflation afforded by theinvention which is the most important ollice of this invention, and infact the presence of the regular valve after the application of thesubstitute valve is superfluous.

Referring to the drawings: Figure 1 is a vertical, longitudinal sectiontaken diametrically through the valve when employed as a substitutevalve, the view being on a large scale. Fig. 2 is a cross section online a02-m2 Fig. 1. Fig. 3 is a section on line @o3- m3 Fig. 1.

Referring to the form shown. .in Figs. 1, 2 and 3, '1 designates theregular valve stem externally threaded and having a reduced upper end 2also externally threaded, The

Specification of Letters Patent. Appiieation ined November 22, isos.'

Serial No. 529,476.

regular valve, not shown, has been removed. The substitute valvecomprises a sleeve 3 provided with a main valve chamber 4 and an outervalve chamber 5, the latter being and communicating therewith through anouter valve seat 6 formed by an abrupt shoulder producing a single lineof contact 7. The sleeve 3 has an externally threaded -reduced portion 8above which is an externally threaded end 9 adapted for the attachmentof the middle of the inflation tube, not shown. The 'lower end Aof thesleevev 3 is provided with internal threads 10 adapted to be screwedonto thev threaded valve stem 1 and the sleeve 3 has an internalshoulder 11 which bears against a flanged thimble 12 having aright-angled edge 13 forming a valve seat with a single line of Contact.Below is a gasket 14 which prevents leakage between v-the upper edge ofthe valve stem 1 and the thimble 12. The thimble 12 has a large bore 15which forms a large air passage for the inlowing air during inflation.

Within the main valve chamber 4 is a double valve comprising a conicalupper valve 16 adapted to coact with the seat 7 and a conical lowervalve 17 adapted to coact with the seat 13, a cylindrical shank 18extending between the two valves with a shoulder 19 formed immediatelybelow the upper valve 16. A coil compression spring 20 is interposedbetween the shoulder 19 and the thimbleV 12 and normally holds the 16 incontact with the seat 7, thus effecting a closure at this outer seat.Extending above the upper valve 16 is an extension 21.

22 designates a cap internally threaded and adapted to be screwed to thethreaded portion 8 andv provided with an internal boss 23 which isadapted to bear against the upper end of the valve extension 21.

In operation, the valve having been applied as indicated in Fig. 1, whenit is desired to inflate the tire, the cap 22 is removed and theinflation tube, not shown, is screwed on the threaded end 9 and air isforced through the passage 5 and overcomvalve 16, thereby opening thevalve seat 7 and the air then flows through the main valve chamber 4,thence through .the air passage 15, through the stem 1 into lthe tire.Upon any relaxation in pressure above the of less size than the mainvalve chamber 4' ing the spring 20 forces down the upperv Patented Got.10, 1911.

the flange of the thimble 12 double valve elevated with the outer valvev upper valve 16 the spring 20 immediately closes the upper valve 16against the seat 7, thereby preventing backward passage of air which hasentered the main chamber 4. After the inflation has been accomplished,the cap 22 is screwed onto the threaded por tion 8 and as soon as itsboss 23 strikes the extension 21 it pushes down the double valve,thereby opening the valve 16 and closing the lower valve 17. The momentthat the upper valve 16 is thus opened, air from within the main chamber4 passes into the upper smaller chamber 5, so that the air pressurewithin chamber 5 equalizes with the pressure within the tire. Continueddownward movement of the cap 22 soon brings' the lower valve 17 intocontact with the seat 13 against which seat it is tightly forced withawedging action due to its conical shape, so that a closure against thelower seat of great strength is effected, which positively prevents theair from within the tire passing outwardly past the seat 13. @wing tothe conical shape of the lower valve 17, together with the single lineof seat contact 13, itis possible to produce an absolutely air-tightunion with comparatively little pressure, and the screw-cap 22 furnishesan ample pressure against the valve extension 21 for this purpose.During the inflation the large passages 5 and 15 permit the air toeasily pass inward into the tire and owing to the line of contactbetween valve 16 and its seat v7', there is comparatively no oppositionto overcome except that of the spring rooster 20 which spring oppositionslight, valve 16 to act as a chamber valve.

What I claim is:

In a valve, a sleeve having internal threadsat its lower end adapted tobe screwed onto a threaded valve stem, the upper end of said sleevehaving a reduced threaded end for the attachment pf an iniiating tubeand having an intermediate threaded portion, said sleeve being providedwith an internal shoulder near its upper end and with an internalshoulder near its lower end, a thimble ternal shoulder and forming alower valve seat, the ,upper shoulder forming an upper valve seat',there being a valve chamber formed between the upper shoulder and saidthimble, a double valve Within said valve chamber comprising two. conesconnected b a shank, a spring resting on said thimble and against theupper cone normally holding the upper cone against its seat, a screw capadapted to be screwed on the external threads of the sleeve, and anextension between said cap and upper cone for mechaniL cally forcing thelower cone against its seat in said thimble.

In testimony whereof7 I have hereunto set my hand at Los Angeles,California, this 13 day of November, 1909.

l ALFRED C. STEWART.

In presence of- Gr. T. HACKLEY, P. H. SHELTON.

is obviously very seated against the lower in! being merely sufcient toclose the i

